How to Build a Room: The Basics

Lead Image
  • 30-50 hours
  • Advanced
  • 6,000-12,000
What You'll Need
Planning materials
Electrical materials
HVAC materials
Building permit
Roofing materials
Wall frames
Marking and digging tools
Trim Work

Building a new room onto on older structure to expand living space is a large project, and it can be just as difficult as building an entirely new structure. However, it can be done. You can find a general guide to building a new room, including things to keep in mind, below.

Step 1 – Drafting a Plan

Before you start purchasing materials, you need to have a rough draft of the room you want to build. Your draft will become your plan for building, and it should include architectural points, shape, size, floor layout, and other aspects of your room. You can use this rough blueprint to scale to size later to have an accurate building plan.

Step 2 – Acquiring Building Permits

Any time you add on to your home, you will need to get building permits. Check with your local zoning boards on what requirements you need to meet. A building inspector will need to come check on each stage of your work throughout, so you need to follow your plans closely, staying within the parameters set by the local authorities.

Step 3 – Digging the Foundation

Once you have your plans and your permits, you can start to break ground on your new room. You will need to mark out the space and start to dig for the foundation. The foundation should be as flush with the existing home as possible. In addition, you should use a good support system for your foundation, so the amount you need to dig will vary depending on the site and how much space you have to work with.

Step 4 – Erecting the Walls

After the foundation is ready, you can begin erecting the walls. Since this just an addition and not a full-scale house, the frame won’t take too long to construct. Once the frame is constructed, the walls can be brought in. For small room additions, you can get these prefabricated at a lower cost than building them onsite.

Step 5 – Installing Roofing

The next step is to install the roof. This is necessary because all the work that comes after this point needs to be protected by the elements. Your room’s roofing style will depend on the type of material you have on the rest of your home’s roof. While you can do this yourself, you may want to hire a professional to ensure the old roofing lines up with the new roofing.

Step 6 – Completing Electrical Work

Once the walls and the roof are up, you can begin on the electrical wiring and HVAC system. Because you’ll be working with electricity and duct work, it’s best to have an electrician and a qualified HVAC specialist take care of this part. Unless you have extensive experience, this electrical is not common do-it-yourself work.

Step 7 – Adding Insulation and Drywall

The next step is to add insulation and then hang the drywall. This is something that you can do yourself with little experience. You'll likely need a friend to help you carry and hang the drywall. If you use fiberglass insulation or other products that are toxic to breathe in, you'll need to wear a face mask and safety glasses.

Step 8 – Adding Finishing Touches

Your new room is now ready for a fresh coat of paint, flooring, trim work, and doors. Once you have built the room, these finishing tasks will be easy to complete.